1. Field of the Invention:
The present invention relates to a copying machine and, more particularly, to a copying machine capable of discharging recording paper to the outside of the machine in the event of a separation failure after the transfer of the image.
2. Description of the Prior Art:
In the copying machine hitherto proposed and used, an electrostatic latent image formed on an image retaining member is developed to form a toner image which in turn is transferred from the image retaining member to a recording paper. The recording paper is then separated from the image retaining member and is discharged to the outside of the machine after fixing the image.
Various methods have been used for separating the recording paper from the image retaining member. For instance, a separation electrode is used to electrostatically neutralize the charge on the recording paper to separate the latter. It has been also adopted to use a movable separation claw which is temporarily brought into contact with the surface of the image retaining member to separate the recording paper. In some cases, the separation electrode and the separation claw are used in combination.
These conventional separation methods, however, could not achieve a perfect separation. Namely, it is often experienced that the recording paper does not come off from the image retaining member after the transfer of the image and runs off the correct passage of paper to cause a problem of separation failure.
In conventional copying machine, when a separation failure has taken place, the failure is detected by a sensor which produces a signal to temporarily stop the operation of the machine. The operation is started again after the removal of the failure paper. In an ordinary machine, the failure paper is removed manually by a hand inserted into the machine. Unfortunately, in most cases, there is not sufficient room for insertion of the hand around the failure paper. Therefore, usually, the copying machine incorporates a paper conveying means (referred to as guiding device, hereinafter) adapted to form the passage of the recording paper and capable of being moved to make the passage accessible, as a failure release device.
Even with such a guiding device, however, the removal of the recording paper closely sticking to the drum surface has to be made by hand, often resulting in inconveniences such as damaging of the drum surface, scattering of toner particles and so forth.
In order to overcome this problem, the present inventors have proposed, as in the specification of the Japanese Patent Application No. 124,107/1980, a separation failure releasing device having a separation means adapted to separate failure paper from an image retaining member in response to the opening operation of a guiding device movable to open the passage of the recording paper. This proposal, however, is not satisfactory in that it still demands the manual ejection of the separated paper to thereby impose problems such as waste of time and contamination of hand and cloth with toner particles.
The present inventors have proposed also a machine, as shown in the specification of the Japanese Patent Application No. 130,227/1980, capable of eliminating the manual work for ejecting the separated failure paper and without causing damaging of the image retaining member and other parts for forming the image to improve the efficiency of the work. More specifically, this copying machine has a first separation means adapted to separate the recording paper from the image retaining member after the transfer of a toner image from the latter and to eject the separated paper to the outside, and a second separation means disposed at the rear side of the separating position and capable of separating the recording paper without fail so that, in the event of a separation failure by the first separation means, the operation of the paper conveying means and the image retaining member is not stopped but continued to make the second separation means separate the paper which could not be separated by the first separation means and discharge the separated paper to the outside.